December 28, 2025 6 min read Mike Johnson
Every year, thousands of people are injured by garage doors in the United States. While modern garage doors are designed with safety in mind, understanding how crush prevention systems work and maintaining them properly is essential for protecting your family.
A standard residential garage door weighs between 150 and 400 pounds, depending on its size and construction. When this weight is in motion, it can generate significant force. Without proper safety systems, a closing garage door can cause severe injuries or even death.
Children and pets are particularly at risk because they may not understand the danger or may move too quickly to be seen by adults. Elderly individuals and those with mobility challenges also face increased risk.
Photoelectric Sensors
The most common crush prevention system uses photoelectric sensors mounted near the floor on either side of the door. These sensors emit an invisible infrared beam that, when broken, signals the opener to stop and reverse the door's motion.
Federal law has required these sensors on all garage door openers manufactured since 1993. If your opener doesn't have them, it's time for an upgrade.
Pressure Sensitivity
Modern openers also include pressure-sensitive systems that detect when the door encounters resistance while closing. If the door contacts an object, the system automatically reverses direction. This serves as a backup to the photoelectric sensors.
Smart Sensors
Advanced systems now include cameras and motion sensors that can detect people and objects before the door begins closing. These systems provide an additional layer of protection beyond traditional sensors.
Regular testing ensures your crush prevention systems are functioning properly. Here's how to test each component:
Testing Photoelectric Sensors: 1. Close the garage door 2. Place an object (like a cardboard box) in the door's path 3. Press the close button on your opener 4. The door should reverse immediately when the beam is broken 5. If the door doesn't reverse, clean the sensor lenses and check alignment 6. If problems persist, call a professional
Testing Pressure Sensitivity: 1. Close the garage door 2. Place a 2x4 board flat on the floor in the door's path 3. Press the close button 4. When the door contacts the board, it should reverse 5. If it doesn't reverse, the sensitivity needs adjustment
We recommend testing these systems monthly and always after any work is done on your garage door.
Misaligned Sensors
The photoelectric sensors must be perfectly aligned to function properly. Bumps, vibration, or settling can cause them to shift out of alignment. Signs of misalignment include the door reversing immediately after you press close, or indicator lights that blink rather than remaining steady.
Dirty Sensor Lenses
Dust, cobwebs, and dirt can block the infrared beam, causing false triggers or preventing the sensors from detecting obstructions. Clean the lenses regularly with a soft cloth.
Wiring Issues
The wires connecting sensors to the opener can become damaged over time. Look for frayed, pinched, or exposed wires, and have them repaired immediately.
Improper Sensitivity Settings
If the pressure sensitivity is set too low, the door may not reverse when it should. If it's set too high, the door may reverse unnecessarily. A professional can adjust these settings correctly.
If your garage door opener was manufactured before 1993, it may lack essential safety features. Even if it seems to work fine, the risk to your family isn't worth the savings of delaying an upgrade.
Modern openers with comprehensive safety systems are affordable and include many additional benefits like smartphone control, battery backup, and quieter operation. The peace of mind alone is worth the investment.
At Smithfield Garage Doors, we include a comprehensive safety inspection with every service call. Our technicians test all safety systems, check alignment, and verify proper operation. We'll also identify potential hazards and recommend solutions.
Safety systems work best when combined with education. Teach children that garage doors are not toys and that they should never run under a moving door. Designate a visible spot where everyone should stand when the door is operating.
Crush prevention systems are not optional extras.they're essential safety equipment that protects your family every day. Maintain these systems properly, test them regularly, and don't hesitate to call professionals when you notice any issues.
Contact Smithfield Garage Doors at (984) 251-1619 for a safety inspection or to upgrade your garage door opener with modern safety features.